Zika, doping and venue problems dominated the opening day of the U.S. Olympic Committee's media summit on Monday as officials were pushed on athlete health and safety for this year's Rio Olympics.

Unlike previous Olympics where high-level security issues dominated the buildup to a Games, it is the mosquito-borne Zika virus creating jitters with the Rio Summer Games only five months away.

Not once during a 40-minute briefing were USOC chairman Larry Probst or CEO Scott Blackmun asked about security but they were bombarded by questions about what was being done to protect the 815 U.S. competitors at the Olympic and Paralympic Games from the Zika virus.

Rio officials are also dealing with concerns over the polluted waters where the sailing competition will take place, construction delays at the cycling and athletic venues, slow ticket sales and a doping lab that is on the verge of being declared non-compliant by the World Anti-Doping Agency (WADA).

But in the United States, Zika is being viewed as the biggest threat for Rio-bound athletes.

The U.S. Olympic Committee is taking steps to limit any risk but said it will leave the final decision on whether to travel to Brazil up to individual competitors.

The virus, linked to a spike in the rare birth defect microcephaly, has hit Brazil hard and has spread through much of Latin America and the Caribbean, raising concerns for athletes planning to compete in Rio De Janeiro, particularly those thinking of having children after the Games.

"It is going to be up to each individual athlete to make his or her decision," said Blackmun, adding that athletes will be given mosquito nets and bug spray while additional medical staff could be brought on to deal with concerns. "We don't want to be in the business of making health policy."

The doping scandal that has left Russian track and field athletes in Olympic limbo was also being felt in Los Angeles, as American medal contenders wait to see if the drug-tainted nation will be allowed to take part in Rio.

WADA said on Monday that it was dismayed by revelations in a German TV documentary that contained fresh allegations of malpractice in Russia's anti-doping system.

Russia has been suspended from international track and field in the wake of a report exposing widespread cheating and corruption and has been ordered by world athletics' governing body, the International Association of Athletics' Federations (IAAF), and WADA, to show evidence of a change of culture and practice in fighting doping.

The country, second only to the United States in the sport's pecking order, will be allowed to return to competition, including this year's Olympics only when it can prove that it has met a series of conditions regarding its anti-doping operation.

"Things just continue to be uncovered ... I'm not totally confident," said Alysia Montano, an American middle distance runner who finished fifth at the London Olympics behind two Russian athletes facing doping bans. "I want to say, yes, it's going to be 100 percent clean but every time I try to say that, I just hope. My confidence is still a little thin."

Casting another shadow over anti-doping efforts, the Brazil lab that will test athletes during this year's Olympics is in a race to fully conform to global regulations by a WADA-imposed March 18 deadline or have testing for the Games moved elsewhere at considerable cost.

WADA stripped the $25 million Laboratorio Brasileiro de Controle de Dopagem of its accreditation in 2013 because it failed to meet required standards, re-instating it last year.